Fuel briquette



Nov, 19, 1940. R. T. BOWLING FUEL BEI QUETTE Filed March 18, 1959 ROBERTT. BOWLING Snvcmor F'G'?" W Jn l Cmomegl txamner Patented Nov. 19, 1940UNITED STATES txaminer PATENT OFFICE FUEL BRIQUETTE Application Marchy18,

4 Claims.

My present invention relates to an improved fuel briquette which may bemanufactured from any vegetable ber, such as wood, bagasse, or the like.

5 My briquette is in the form of a solid cylinder of a convenient lengthand diameter for handling, and is highly suitable for heating andcooking purposes. Through the principles involved in the construction ofmy fuel briquette I am able to produce a durable article of manufacturewhich may be readily transported great distances and will stand allmanner of conditions met in the usual course of such transportation.Hithertofore briquetted fuel has tended to disintegrate in the 16presence of heat and humidity as well as from the shocks receivedthrough being handled in shipment.

It is a characteristic of my briquette that it is bound into asubstantially sized, uniform unit by n means of inherent resins,lignins, gums, and moisture so that a foreign binding or bonding agentis unnecessary. It has, however, proved advisable in certain instancesas when forming decomposed vegetable matter, such as coal and the illike, to bond the material, due to the extreme dry condition of the rawmaterial. Another characteristic of my fuel briquette is the hard,smooth, glazed combustible jacket that is presented and is apparent inthe briquette when it has been 80 formed according to the principles ofmy invention, as shown in Patent No. 1,990,632. This jacket isrelatively non-hygroscopic and therefore the briquette may be subjectedto a high degree of humidity without any effect whatsoever upon $5 thelog. 'Ihis jacket further serves to make more easy the handling ofbriquettes during the stages of shipment and in delivery to the ultimateconsumer. The smooth, hard surface permits the handlers to convey thebriquettes from one eleva- 40 tion to another by sliding them alongtroughs.

Another essential characteristic of my briquette is the construction ofthe artificial log by the formation of a continuous helically spirallamination which under the extreme pressure to which I 45 subject thematerial closely adheres together to present a homogeneous article.

More particularly am I concerned herein in the manner by which I formthese. laminations so that they are distorted to form corrugations 50which nest one upon the other more securely than has heretofore beenpossible. In earlier efforts to produce the laminated briquettes theusual form of the lamination was flat or ribbon-like in cross section,thus producing an article which,

55. due to its Weight, had a multitude of lines of 1939., Serial N0.262,754

cleavage so that if the article should ever come to rest upon an unevensurface either violently during handling or be under a great weight dueto stacking for storage, the article would separate on these naturallines of cleavage into two or more smaller pieces. Such breakage isnaturally undesirable and the solution of the problem by eliminatingsuch breakage or cleavage will greatly open the market for suchartificially formed fuel briquettes.

The manufacturing operation of forming fuel briquettes according to myinvention comprises the use of dry or seasoned fibers cast off as refusefrom many manufacturing operations. In the woodworking industry greatquantities wdust wood shavings, and waste woods normally are discardedby the manufacturer who has no further use for them. In the sugarindustry the fiber, bagasse, presents a refuse problem that is difficultfor the sugar manufacturer to cope with and the same is true in manyother industries.

One of the early steps usually necessary in the formation of briquettesis to dry the bers so that the moisture content forms a relatively lowpercentage of the entire mass of raw material. This material is thenreduced in suitable grinding machinery so that it is finely comminutedand of a uniform size. The material is then conveyed to suitablemachinery and undergoes the steps of my process which briefly consistsof pressing, heating, and cooling to the result that a solid cylindricalproduct suitable for fuel purposes is produced.

For the purposes of further description it will be assumed that I amspeaking entirely of,wood fiber but it is to be understood that in thismanner I do not intend to limit my invention in any way.

In the pressing stage of my process the bers are subjected to graduallyincreasing pressure through mechanical means, whereby the bulk of rawmaterial fed to the machinery is formed into gradually more denselaminations in the form of a helically spiral ribbon of material. Withthe increase of the pressure upon the material a high degree of heat isproduced which converts or changes the inherent gums, resins, lignins,and moisture into a highly efficacious bonding agent. During thispressing stage the spiral ribbon referred to above may be distorted bythe formation of corrugations which follow the conformation of thehelically spiral laminations.

When the spiral laminations have been pressed into a suitable die in thepresence of a high degree of heat, they are permitted to cool during astage of the process and are later extruded from' the die in the form ofa solid cylindrical fuel log or briquette. During the heating andsubsequent cooling stages of my process the bonding materials thoroughlyimpregnate the fibers and bind them together and, to a considerableextent, are driven to the outside of the cylinder Where, upon cooling,they present, along with the fibers therein, a hard, glazed, durablesurface.

It should be apparent through the pressure and the heat generated thatthe cylindrical briquette is composed of a quantity of wood fibers fromwhich practically all of the elasticity has been expelled and thematerial is reduced to its barest structural matter. Fuel briquettesformed with the hard, glazed outer surface and of the spirallycorrugated spiral laminations are also extremely slow burning andtherefore highly desirable for fuel purposes.

Disintegration which formerly took place in burning the ordinaryspirally laminated briquette is not present in the article hereindescribed with the consequence that re does not have ready access to theinterior of the laminations and must burn slowly and evenly over theentire outer surface. The quantity of the bonding material present inthe outer jacket of the cylinder also assists the ignition of mybriquettes in use.

In the accompanying drawing, forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame,

Figure 1 is a view in elevation showing my briquette;

Figure 2 is an end view of one of my fuel briquettes;

Figure 3 is a diametric sectional view through a portion of a fuelbriquette of my invention.

Figure 4 is a side elevational view of the present die head employed inconnection with the general structure disclosed in Patent No. 1,990,632to produce the fuel briquette of this invention,

Figure 5 is a Vertical sectional view through the die head taken alonglines 5-5 of Figure 6; and

Figure 6 is a front elevational view of the die head.

The briquette as a whole is indicated by the numeral I and is composedof a continuous series of helically spirally wound laminations II whichare highly and successively compressed to form a unit of fuel and thecommon center I2 of the laminations provides a solid zone extendedthroughout the length of the cylinder along its longitudinal axis. Eachcross section of a lamination is distorted as may best be seen inFigures 2 and 3 so that corrugations I3, I4, and I5 are produced in thelaminations I I immediately following the formation of the helicallyspiral laminations. The corrugations in each successively formed spirallayer register with those of the preceding layer and are securelycompressed together under from twenty to forty thousand pounds pressureper square inch. Under this high compression the bonding materials bindthe fibers, as well as the successive laminations, together into ahomogeneous mass as uniformly dense throughout a possible.

Because, however, the succeeding laminations must be compressed upon thepreceding laminations, a tendency to cleave or shear along the lines ofthe laminations has existed. The interlocking or nesting together of thecorrugations in the laminations effectively removes this objection andthe ultimate of homogeneity results. In the earlier stage of thecompression the material from which the briquettes is to be formed iscompressed into laminations substantially wider and thicker than thelaminations I I and these previously formed laminations are subsequentlycompressed into the relatively thin laminations II shown in Figure 3.

In the process of forming the briquette, the comminuted material in asubstantially dry or seasoned state is laid in a continuous spiralribbon and subjected to high pressures. This presure creates internalheat and the heat thus produced liquidizes the natural rosins, etc. inthe material and permeates the entire fibrous mass.

The briquette of Figure 1 is formed in a cylindrical mold which issupported along with other similar molds in a die wheel. The entireseries of molds is enclosed by suitable jackets and Water for coolingpurposes is circulated therethrough.

When the ultimate compression is reached and the cylindrical die is lledwith spirally laminated material the water around the outside of the diein which the material is formed, cools and sets the binding or bondingmaterials and forms the hard, smooth, glazed surface I6 of thebriquette. While this glazed surface is highly combustile it is alsonon-hygroscopic, thus serving to protect the outer faces of thebriquette froml deterioration due to moisture, such as humidity in theair, and it also serves as an envelope for the laminated structurewithin.

Briquettes formed in my machine are usually of a convenient size forhandling, being approximately twelve inches long and four inches indiameter and having an approximate weight of eight pounds each. Bulkshipments and bulk sales are the customary manner of delivering thearticle to the market. In certain instances these briquettes may beconveniently packaged in cartons of any desirable number for delivery insmaller quantities.

The presence of the converted lignins, resins, gums, etc., as bindingand bonding agents makes the log relatively easy to ignite and I havefound by chipping portions of the lamination from an end of a log, thatthey can be readily ignited from an ordinary match which will producesufficient heat to ignite the bulk of the log.

The die head shown in Figures 4, 5, and 6 is identical with the die headshown and described in my copending patent application, Serial No.262,753, filed March 18, 1939. It has a spindle or shank I1, whichsupports the head I8 that is a portion of a screw and has the cam faceI9. The cutting edge 20 extends in a radial direction from the peripheryof the head to the periphery of the spindle in the usual manner.

The head also has the slot 2I through which the material passes to beiinally compressed by the cam face I9. Upon the face I9 I form one ormore ribs 22, which, as the ribbon of compressible vegetable matterpasses through the slot 2l, act upon the ribbon to form the corrugationsI3, I4, and I in the helically spiral ribbon. These corrugations conformto the lay of the ribbon in the cylindrical briquette and function aselsewhere described in this specification.

Because of the uniformity of the size and weight of my briquettes, thenormal heat values per unit of length of the article are readilydetermined. It is thus possible to predetermine the heat content of thecomplete briquette or any given portion and relatively criticaltemperatures can be obtatined for cooking and burning. It should beapparent that many economies can be effected through the use of mybriquettes as fuel.

The high degree of compression to which the material from my briquettehas been subjected expels all the air, due to the fact that the cellularstructure present in all fibers is destroyed. When the fuel is burnedthe danger of ying sparks common with many fuels is eliminated as Wellas the self-destruction of the fuel. Dispersion of unburned parts of thelog throughout the fireplace or furnace, whereby a considerable portionwould be discarded as ash, is also eliminated.

Because the laminations and their corrugations restrain the separationof the log through expansion, oxygen is not permitted access to theinterior of the laminations and the ame area is confined o the outersurfaces of the log.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is:

1. A solid cylindrical briquette formed of helically spiral ribbonlaminations of compressed vegetable matter that is characterized byhaving Lxaminer corrugations conforming to the lay of said spirallaminations.

2.- A solid cylindrical briquette formed of helically spiral ribbonIlaminations of compressed vegetable matter that is characterized byhaving corrugations conforming to the lay of said spiral laminations,the corrugation of one coil of the helically spiral ribbon laminationsnesting in the corrugation of the preceding coil.

3. A solid cylindrical briquette formed of helically spiral ribbonlaminations of compressed vegetable matter that is characterized bybeing ridged on one face of said spiral ribbon laminations and groovedon the opposite face thereof, said ridged and grooved faces conformingto the lay of the spiral laminations.

4. A solid cylindrical briquette formed of helically spiral ribbonlaminations of compressed vegetable matter that is characterized byrbeing ridged on one face of said spiral ribbon laminations and groovedon the opposite face thereof. said ridged and grooved faces conformingto the lay of the spiral laminations, and the ridged face of onelamination nesting against the grooved face of the preceding lamination.

ROBERT T. BOWLING.

